| 摘要 |
An ACPD measuring system includes an oscillator 10 capable of operating at a plurality of different frequencies or continuously variable over a given frequency range. Alternating current is applied to a sample 14 under test at a number of different frequencies in succession in order to provide a corresponding number of different skin depths and the potential drop across two points 20, 22 on the sample surface due to the current flow is measured. The composition of the sample at various depths beneath the sample surface may be deduced from a graph of the measured potential drop against the square root of the applied frequency. <IMAGE> |
